Applications Horn (acoustic)

1 applications

1.1 horn loudspeakers

1.1.1 use of surroundings part of horn


1.2 material handling sound horns
1.3 horn-loaded musical instruments

applications

a traditional reed bulb horn

acoustic horns used in:

horn loudspeakers
brass , woodwind musical instruments
vehicle horns such used on cars, trucks, trains, boats, , bicycles
megaphones, used lifeguards @ public swimming pools.
ear horns, used people hard of hearing (the human ear having form of horn)
pickup horns, used e.g. on acoustic phonograph players

horn loudspeakers


a patent horn loudspeaker

loudspeakers built horn-shaped enclosures or use horns. higher-frequency elements (tweeters , midranges) use horns, acoustic diffraction lenses spread sound waves in horizontal pattern @ ear-level , limit vertical pattern. audio driver (e.g., speaker cone or dome) mounted @ small, inner end. horn loudspeakers efficient, have sharp cutoff frequency, depending on size, little sound output below. bass sounds produced conventional speaker cones, since (straight or folded) horn sufficient reproduce 20 hz have 12 ft. (4 meters) long, except when building, ground surface, or room considered part of horn.

use of surroundings part of horn

large bass speakers take advantage of surroundings part of horn. example, can put in corners of room, walls act part of horn. outdoors, ground can form part of horn surface, , partial horn can provide impedance match ground, or 1 or more walls, @ low frequencies.

material handling sound horns

in agriculture, , dry material handling generally, sound horns used start material flow or force release of impacted materials. in grain silo, such horn may mounted inside silo , sounded silo emptied loosen stuck granules. typically, these use fundamental frequency around 120–250 hz, 120 db spl, , powered compressed air. called acoustic cleaners or acoustic horns.

horn-loaded musical instruments

many wind instruments have kind of flaring bell shape. these not exponential in configuration, , used modify standing wave patterns of instrument, , thereby musical notes can produced.

flared section of bore in many instruments conical. first let s @ spacing of frequencies. in page pipes , harmonics, saw closed conical pipes have resonances frequencies both higher , more closely spaced of closed cylindrical pipe. 1 can think of introducing conical or flared section of pipe raising frequencies of standing waves, , raising frequencies of low pitched resonances of all. bell contributes effect: in rapidly flaring bell, long waves (with low pitches) least able follow curve of bell , reflected earlier shorter waves. (this because wavelengths longer radius of curvature of bell.) 1 might therefore long waves see shorter pipe.

this has effect of providing both brassy sound of horn instruments versus woodwinds or metal instruments lack flare, , of increasing perceived loudness of instrument, harmonics in range ear sensitive delivered more efficiently. however, enhanced radiation in higher frequencies means definition less energy imparted standing waves, , less stable , well-defined notes in higher registers, making instrument more difficult play.